Is this one.....?I'm at Autotech in Gus's office. The first thing I did. No when I go to leave ...GAME OVER. Apparently I was supposed to do something with the soap and mop pail first, but I didn't.Any clues?Thank caz

This is what RJ Roman's walkthrough says:If you are playing in the ENT mode you simply look for Dag Horton’s office door and enter. (Remember the cufflink with the initial DH) However, if you are playing in the GP mode when you enter the hallway turn left and rush into the storage room. While in the room get the box of soap from the shelf and the mop.

Timing is of the essence here, so, this might be a good place to save your game. You have a security guard to contend with in this area in the GP mode. Wait until the security guard passes and you hear the door shut. Rush straight down the hall to where you see the bucket and mop the floor. There will be a cinematic scene of Tex mopping the floor. When it’s over, open the door beside the bucket to trigger the alarm, then rush back into the storage room and close the door behind you. When the guard makes his rounds again he’ll slip, fall and be knocked out unconscious. In the next cinematic scene Tex will drag his body in the closet and lock him in with the mop handle. Now, you can enter Dag Horton’s office.

Once inside Dag Horton’s office look at the photograph on the wall. It is a picture of Dag Horton. Now you know what he looks like. Open the CD player and get the file cabinet key. Move the book on the desk and get the post-it not with Rev. Gary name on it. (Umm..How does Crazy Gary fit into all of this?) Next, open the bottom drawer and get necklace that belongs to Sandra Collins. Looks like we’ve found our Black Arrow Killer. Now, open the file cabinet on the right side and get the photos. Before you leave the room, look on the bookcase and get the Meister lock key. It opens the lock to the water tower on the roof of Rusty’s Funhouse.

Reading over a walkthrough, it sounds to me like you do indeed have to get the mop and pail before entering Dag's office if you are in GP mode but not if you are playing in Entertainment mode. Have you tried switching to Entertainment mode while in Dag's office to see if that allows you to proceed?

Otherwise, it sounds like you are going to have to reload an earlier saved game to get past this.